Exam 16: Time-Series Forecasting

TABLE 16-6 The president of a chain of department stores believes that her stores' total sales have been showing a linear trend since 1990.She uses Microsoft Excel to obtain the partial output below.The dependent variable is sales (in millions of dollars),while the independent variable is coded years,where 1990 is coded as 0,1991 is coded as 1,etc. -Referring to Table 16-6,the forecast for sales (in millions of dollars)in 2010 is ________.

TABLE 16-4 The number of cases of merlot wine sold by a Paso Robles winery in an 8-year period follows. -Referring to Table 16-4,a centered 3-year moving average is to be constructed for the wine sales.The result of this process will lead to a total of ________ moving averages.

TABLE 16-13 Given below is the monthly time-series data for U.S.retail sales of building materials over a specific year. The results of the linear trend,quadratic trend,exponential trend,first-order autoregressive,second-order autoregressive and third-order autoregressive model are presented below in which the coded month for the first month is 0: -Referring to Table 16-13,what is the p-value for the t test statistic for testing the significance of the quadratic term in the quadratic-trend model?

TABLE 16-13 Given below is the monthly time-series data for U.S.retail sales of building materials over a specific year. The results of the linear trend,quadratic trend,exponential trend,first-order autoregressive,second-order autoregressive and third-order autoregressive model are presented below in which the coded month for the first month is 0: -Referring to Table 16-13,the best model based on the residual plots is the quadratic-trend regression model.

TABLE 16-10 -Referring to Table 16-10,the value of the MAD for the second-order autoregressive model is ________.

To assess the adequacy of a forecasting model,one measure that is often used is

TABLE 16-13 Given below is the monthly time-series data for U.S.retail sales of building materials over a specific year. The results of the linear trend,quadratic trend,exponential trend,first-order autoregressive,second-order autoregressive and third-order autoregressive model are presented below in which the coded month for the first month is 0: -Referring to Table 16-13,what is your estimated annual compound growth rate using the exponential-trend model?

After estimating a trend model for annual time-series data,you obtain the following residual plot against time. The problem with your model is that

TABLE 16-13 Given below is the monthly time-series data for U.S.retail sales of building materials over a specific year. The results of the linear trend,quadratic trend,exponential trend,first-order autoregressive,second-order autoregressive and third-order autoregressive model are presented below in which the coded month for the first month is 0: -Referring to Table 16-13,what is the exponentially smoothed value for the 12ᵗʰ month using a smoothing coefficient of W = 0.25 if the exponentially smooth value for the 10ᵗʰ and 11ᵗʰ month are 9,477.7776 and 9,411.8332,respectively?

Which of the following statements about the method of exponential smoothing is not true?

TABLE 16-3 The following table contains the number of complaints received in a department store for the first 6 months of last year. -Referring to Table 16-3,if this series is smoothed using exponential smoothing with a smoothing constant of 1/3,what would be the second value?

MAD is the summation of the residuals divided by the sample size.

TABLE 16-13 Given below is the monthly time-series data for U.S.retail sales of building materials over a specific year. The results of the linear trend,quadratic trend,exponential trend,first-order autoregressive,second-order autoregressive and third-order autoregressive model are presented below in which the coded month for the first month is 0: -Referring to Table 16-13,the best model based on the residual plots is the second-order autoregressive model.

Given a data set with 15 yearly observations,there are only thirteen 3-year moving averages.

TABLE 16-1 The number of cases of chardonnay wine sold by a Paso Robles winery in an 8-year period follows. -Referring to Table 16-1,does there appear to be a relationship between year and the number of cases of wine sold?

The MAD is a measure of the mean of the absolute discrepancies between the actual and the fitted values in a given time series.

The fairly regular fluctuations that occur within each year would be contained in the ________ component.

TABLE 16-5 The number of passengers arriving at San Francisco on the Amtrak cross-country express on 6 successive Mondays were: 60,72,96,84,36,and 48. -Referring to Table 16-5,exponentially smooth the number of arrivals using a smoothing constant of 0.25.

TABLE 16-13 Given below is the monthly time-series data for U.S.retail sales of building materials over a specific year. The results of the linear trend,quadratic trend,exponential trend,first-order autoregressive,second-order autoregressive and third-order autoregressive model are presented below in which the coded month for the first month is 0: -Referring to Table 16-13,what is the p-value of the t test statistic for testing the appropriateness of the second-order autoregressive model?

TABLE 16-13 Given below is the monthly time-series data for U.S.retail sales of building materials over a specific year. The results of the linear trend,quadratic trend,exponential trend,first-order autoregressive,second-order autoregressive and third-order autoregressive model are presented below in which the coded month for the first month is 0: -Referring to Table 16-13,what is your forecast for the 13ᵗʰ month using the first-order autoregressive model?